Here at the House of General Science, we are extremely enthusiastic about science projects. We display this passion at RIT’s annual Imagine RIT creativity festival. Below is information on some of the house’s most recent projects. Check out our gallery page for additional images.
We are currently in the early phases of design for this years lineup of Imagine RIT projects! Soon we will have updates on our progress, and an insight into the year to come.
A Jacob’s ladder operates under the principle that hot air rises. A hot electrical arc is created at its base due to a high potential difference, which then rises up in a gap between a separating pair of long conductors. This draws the arc up the length of the conductors, increasing width until the potential difference becomes too weak to maintain an arc and breaks. A new arc is then formed at the base and the process repeats.
Within our Jacob’s Ladder, the high voltage arc was created via a 15,000V 60mA high voltage power supply. One major problem with conventional Jacob’s ladders is that the ignition of the arc can be very chaotic and inconsistent. To maintain consistent and repetitive ignition of sparks, we implemented a clever electrode design on the base. This electrode is called a Gabriel Electrode and it ran perpendicularly between the two base electrodes of the ladder. This electrode was connected to one of the base electrodes via a specialized 3MΩ high voltage resistor. Due to the smaller gap between the Gabriel electrode and its neighbor, the arc was guaranteed to form at that location. Once an arc begins, the current flowing through it, drops the voltage across the series connected resistor via Ohms Law. This voltage drop makes the remaining high voltage electrode appear favorable to the Gabriel electrode and thus the arc jumps over the extra distance. This arc then begins to climb up the “ladder” due to the fact that hot air rises.
This entire electrode arrangement was placed inside a large cast acrylic tube for a few reasons but most of all due to safety reasons. High voltage is dangerous! The tube itself was 8 inches in diameter with a wall thickness of a quarter inch. This large diameter, thickness, and the dielectric properties of acrylic combined to form a suitable insulator between the arc formed and an observer. Furthermore, this tube acted to reduce outside influences on the arc such as air currents and oscillations in the electrodes. The entirety of this arrangement was mounted on and housed in a display case, custom made by the Rochester Museum and Science Center (RMSC) Staff.
Currently the Jacobs ladder is on permanent display in the Rochester Museum and Science Center’s Energize it Exhibit! An amazing accomplishment for HOGS!
The Jacobs ladder was made possible by the support and donations from The RIT College of Science, The Rochester Museum and Science center, Sign a Rama in Rochester, and San Diego Plastics in California. We thank them for all the help and materials they provided!
The HoGS wave machine was yet another huge hit at Imagine RIT 2011! The HoGS wave machine was engineered to replicate and model the path of various waves. It consisted of multiple wooden skewers evenly spaced out and sandwiched between two very long strands/chains of duct tape, which then had rubber stoppers attached to either end of each skewer. The balanced weight of the stoppers along with the equidistant spacing of the skewers allowed for even the smallest touch to translate into a visually clear wave pattern. The touch of an individual (the “pulse”) would originate at the point of contact (generally the ends of the machine) and then propagate down the length of the tape until it reached the other fixed end which would then cause it to invert and translate back down the tape; much like any other wave.
If two waves were to be formed, one from each end by two people, they could be observed as they traveled the length of the wave machine. Either destructive or constructive interference was clearly visible at the intersection point of the two waves.
The HOGS wave machine stretched across the atrium of RIT’s College of Science building on one of the upper floors where it was accessible to anyone. The 2011 wave machine is currently in use by the Rochester Museum and Science Center. A new wave machine is under construction for Imagine RIT 2012, which will be longer and even more epic!
Hydrogen Cannon Project
For the 2011 Imagine RIT, HoGS created a hydrogen powered PVC combustion device. The idea of the hydrogen “cannon” was to, via electrolysis, form hydrogen and oxygen in an enclosed chamber in which if we applied a spark to it, would cause a contained combustion forcing a sealed projectile to fly up into the air/through a contained acrylic tube. As the foundation for combustion, electrolysis is the separation of hydrogen and oxygen of an ionic solution by the passing of current through Anode and Cathode electrodes. After the gaseous fuel fills up the chamber, a simple spark in the chamber causes the conversion of chemical energy to heat energy via combustion. This causes an extreme pressure change within the chamber that autocorrects itself by expansion of the combusted gases. This resulting pressure change takes the form of mechanical energy and launches the lightly sealed projectile into the air.
The HoGS hydrogen “cannon” was constructed from multiple pieces of PVC piping secured together along with our own group of electrodes, projectile and acrylic projectile tube. The electrodes we created were simple 4”x4” sheets of aluminum flashing which we submerged in the most practical and desired electrolyte solution; one table spoon of table salt for every 2.75 liters of purified water. Dasani bottled water works very well. The electrolysis of our electrolytic salt water solution is then ignited by electrodes from a basic gas grill lighter. Finally, the following combustion sends the projectile made of 2” aluminum tubing with an acrylic nose cone for resealing capabilities through a 6ft x 2” diameter clear extruded acrylic barrel.
Hydroponic Garden Project
Our goal was to create a hydroponic garden from house hold materials that would be relatively easy to replicate.
This procedure holds recommendations for making your own hydroponic garden similar to the one displayed at Imagine RIT by the House of General Science.
- Feel free to try any plants you would like, keep in mind plants such as tomatoes will need a method of support for the stem.
- Cut your 10 foot gutter into two 5 foot lengths, this makes water circulation easier. (Each gutter should hold about 10 liters of water)
- Place the end caps on the gutters.
- Using foam board, make a cover for the nutrient solution. Cut the board to the size of the gutter, and cut openings for the planters.
- When the planters are placed in the cover there should be space between the bottom of the planter and the bottom of the gutter.
- When planting seeds it is important that they do not get waterlogged, so to accomplish this it is recommended you add a packing material to the planters, this can be anything, we used one similar to Styrofoam. Then place the planters into the gutters.
- The best method of fertilizing the plants is to mix the fertilizer into 2 gallons of water, to get proportions correct read the back of the fertilizer package (make sure it is liquid fertilizer!)
- Move your set up close to a window, if this is not a viable option, you can use a plant growth light instead.
- Add the Nutrient Solution to the gutter.
- Add the fish tank bubbler into the nutrient solution making sure it stays submerged; you can use a long air stone for this.
- Fertilizer will need to be changed weekly, along with an occasional gutter cleaning.
- The seeds need to be in some water when planted, they should begin to germinate within a week of being planted.
- You may encounter a problem with either mold or algae
- As plants continue to grow you will want to increase the strength of the fertilizer to encourage growth, read all instructions on the fertilizer bottle; be cautious, as this can encourage algae growth as well.
Van Der Graaf Generator
The Hogs Van Der Graaf is a 6 foot high monster! The Van Der Graaf generator was essentially the main attraction in the innovation center at Imagine RIT 2010. Capable of outputting more than three quarters of a million volts (750,000V), the Van Der Graaf produced sparks up to three feet in length.
The Van Der Graaf base structure was fabricated completely from laser cut acrylic and housed the main drive motor, positive roller, and positive collector comb. This base supported a 6 inch diameter, 5 foot extruded acrylic tube which encased the main drive belt and supported a 22 inch chrome plated hollow steel sphere. Within the sphere resided the negative roller and negative collector comb. The dielectric drive belt passed over the two rollers cycled from the base to the sphere top. At the bottom of the base (the ground) the belt rips electrons off the roller (making it positive) which are replenished by the bottom collector comb. The belt then brings those electrons to the top sphere. In the sphere, the negative roller collects electrons from the belt and puts them on the sphere through the positive collector comb. The positive charge on the sphere (holes for the educated) is then transferred to the belt and sent back down to the base, where the process starts again. The cycle repeats itself until enough charge is built up on the sphere to create a large enough electric field to force the air to break down; much like a lightning bolt in a cloud. Break down occurs in the form of a really nice spark.
As you can imagine, three foot 750,000V sparks are pretty dangerous, for this reason, we safely contained the Generator within an encompassing faraday cage. The cages conductive wires cancel any electric field it contains thus protecting nearby people and electronics from harm.
Currently, the HOGS Van Der Graaf generator resides in the Rochester Museum and Science Center (RMSC) where is it used for live science demonstrations and shows. The Van Der Graaf would not have been possible without the help and support of RMSC along with the RIT College of science, and RIT Innovation Center. We thank them for their support.